Electric vacuum brush for vacuum cleaners

ABSTRACT

An electric vacuum brush for vacuum cleaners has a vacuum head having a brush roller chamber through which suction air can flow, and a roller brush mounted to rotate in the brush roller chamber and driven by an electric motor. The vacuum head has a working width that is measured at the outside edges, crosswise to the working direction. The brush roller chamber has an opening at the bottom, delimited by parallel vacuum motor edges, which extends essentially over the working width of the brush roller chamber. The electric motor has a power consumption, measured at motor angle, of a maximum of 80 watts, and the vacuum head has a working width of more than 320 mm.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] Applicants claim priority under 35 U.S.C. §119 of GermanApplication No. 203 08 760.7 filed Jun. 5, 2003.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to an electric vacuum brush forvacuum cleaners, which has a vacuum head having a brush roller chamberthrough which suction air can flow, and a roller brush mounted to rotatein the brush roller chamber, and driven by an electric motor. The vacuumhead has a working width that is measured at the outside edges,transverse to the working direction. The brush roller chamber has anopening at the bottom, delimited by parallel vacuum mouth edges, whichextends substantially over the working width of the brush rollerchamber.

[0004] 2. The Prior Art

[0005] Commercially available electric vacuum brushes for householdvacuum cleaners possess a working width between 280 mm and 350 mm. Inthe case of a working width between 280 mm and 300 mm, motors whoseelectric power consumption lies between 30 watts and 60 watts when themotor is idling are used as the drive unit. Furthermore,battery-operated electric vacuum brushes are known, the working width ofwhich also lies in the indicated range between 280 mm and 300 mm. Thesemotors, too, have a power consumption of approximately 30 watts whenidling. With an increasing working width of the electric vacuum brush,more powerful motors are used to drive the brush roller. Commerciallyavailable electric vacuum brushes having a working width between 300 and350 mm are equipped with universal motors whose power consumption liesin the range between 100 and 150 watts when the motor is idling.Finally, for the commercial sector, electric vacuum brushes having aworking width of more than 400 mm are used, which are equipped withhigh-power universal motors having a power consumption, measured whenthe motor is idling, of 200 watts and up.

[0006]FIG. 1 shows the specific power consumption of commerciallyavailable electric vacuum brushes. The rated power pursuant to EuropeanStandard N 60335 of the electric motor driving the brush roller isplotted as a function of the working width of the electric vacuum brush.The rated power pursuant to EN 60335 is indicated on the label of eachmotor. This rated power is the power consumption of the motor in idle.In the working field shown in FIG. 1, three different ranges can beseen. Narrow electric vacuum brushes for household vacuum cleaners fallinto working range A; these are equipped with permanent magnet motors orconfigured as battery-operated devices. Broad electric vacuum brusheshaving universal motors as the drive unit for the brush roller, also forhousehold vacuum cleaners, fall into working range B. Range C isreserved for electric vacuum brushes for commercial use.

[0007] In the case of vacuum cleaner heads without rotating, drivenbrush rollers, for household vacuum cleaners, energy-efficient vacuumingis possible if the vacuum cleaner head is configured with a relativelylarge working width between 350 mm and 500 mm as described in EP 1 228732 A2. By means of the configuration of the slide plate on theunderside, particularly by means of the dimensions of the opening on thebottom, configured as a vacuum mouth, and the configuration of thevacuum mouth edges, the vacuum cleaner head can be designed so that theair volume, calculated as the product of the air stream and the partialvacuum, does not change, or changes only slightly, with an increasingworking width. At a predetermined air volume, a larger floor surface canbe cleaned as the working width increases.

[0008] There is a fundamental need to reduce the energy consumption ofelectric devices. The manufacturers of vacuum cleaners are optimizingthe power consumption of the vacuum fans. The vacuum cleaner heads mustbe coordinated with the vacuum fans so that satisfactory results can beachieved with the overall system that consists of the vacuum fan and thevacuum cleaner head, both with regard to function and with regard to theenergy demand. The energy consumption for driving a brush roller of anelectric vacuum brush has always been ignored, until now, whenconsidering the energy consumption of the system as a whole.

SUMMARY OF THE INVENTION

[0009] It is an object of the present invention to provide an electricvacuum brush with which large areas can be effectively cleaned, at thelowest possible energy consumption.

[0010] This object is accomplished, according to the invention, with anelectric vacuum brush having the structure and purpose as indicatedabove, by means of combining a power consumption of the electric motor,measured at motor idle, of a maximum of 80 watts, and a working width ofthe vacuum head of more than 320 mm. “Power consumption” is the ratedpower indicated on the label of an electric motor, pursuant to EuropeanStandard EN 60335.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Other objects and features of the present invention will becomeapparent from the following detailed description considered inconnection with the accompanying drawings. It should be understood,however, that the drawings are designed for the purpose of illustrationonly and not as a definition of the limits of the invention.

[0012] In the drawings:

[0013]FIG. 1 is a graph plotting power consumption versus working widthof the vacuum head of commercially available electric vacuum brushes;

[0014]FIG. 2 is a graph plotting power consumption versus working widthof the electric vacuum brush according to the invention in comparison tothe prior art;

[0015]FIG. 3 is an exploded view of the electric vacuum brush accordingto the invention, in a top view;

[0016]FIG. 4 is the section A-A through the object of FIG. 3; and

[0017]FIG. 5 is a view from the bottom of the electric vacuum brushshown in FIG. 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0018]FIG. 2 shows the working range according to the invention, incomparison with the state of the art as explained above. The rated powerof the motor that drives the brush rollers is plotted over the workingwidth of the vacuum head. The working range according to the inventionis characterized by the field D. The working ranges A, B, and C werealready explained above, in the discussion of FIG. 1.

[0019] By means of the teaching according to the invention, it isprovided that the power consumption of the electric motor driving thebrush roller, measured at idle, is not allowed to exceed 80 watts evenin the case of wide electric vacuum brushes whose working width isgreater than 320 mm. It is true that the power required for driving thebrush roller is dependent on the length of the brush roller andtherefore on the working width of the electric vacuum brush, but thepower required can also be influenced by other factors. These factorsinclude the type and arrangement of the equipment of the brush roller,the distance of the bristles connected with the brush roller from thefloor, and other design measures, e.g. the mounting of the brush rollersand the like.

[0020] According to the invention, the working width and the maximumpower consumption of the electric motor that can be tolerated arepredetermined as target values. The predetermined target values can beachieved by means of design measures as well as the selection of themotor. Preferably, a permanent magnet motor is used as the motor. In thetechnical implementation of the teaching according to the invention, aperson skilled in the art can use known measures guided by theprinciples according to the invention.

[0021] According to a preferred embodiment of the invention, the vacuumhead has a working width between 340 mm and 460 mm. Furthermore, it ispreferred that the electric power consumption of the electric motor inidle is less than 60 watts.

[0022] FIGS. 3 to 5 show an embodiment used merely as an example of thestructure of the electric vacuum brush according to the invention. Theelectric vacuum brush shown in FIGS. 3 to 5 is intended for householdvacuum cleaners. The electric vacuum brush consists of a vacuum head 1,a brush roller 3 equipped with bristles 2 in spiral shape, which isarranged in a brush roller chamber 4 of the vacuum head, which chamberis open towards the bottom, and driven by an electric motor 5, and anoutlet connector 6 that is mounted so as to tip or pivot, having atube-shaped end for a connection to a vacuum tube connected with ahousehold vacuum cleaner.

[0023] Vacuum head 1 is made up of a lower housing part 7 and an upperhousing part 8. On the inside of the lower housing part 7, ridges 9 areformed, which separate a flow space from the installation space 10 forelectric motor 5 and an installation space 11 for the electrical devices12. Installation space 10 for electric motor 5 and installation space 11for electrical devices 12 are arranged on both sides of an outletchannel that expands to become the roller chamber. A shell 13 is setonto ridges 9 of lower housing part 7, which shell encapsulatesinstallation space 10 for electric motor 5 as well as installation space11 for electrical devices 12, and forms the flow space within vacuumhead 1. It is evident from FIG. 5 that vacuum head 1 has a working widthW, measured at the outside edges, crosswise to the working direction,and that brush roller chamber 4 has an opening 15 at the bottom,delimited by parallel vacuum mouth edges 14, 14′, which extendsessentially over working width W of brush roller chamber 4.

[0024] Although only at least one embodiment of the present inventionhas been shown and described, it is to be understood that many changesand modifications may be made thereunto without departing from thespirit and scope of the invention as defined in the appended claims.

What is claimed is:
 1. An electric vacuum brush for a vacuum cleanercomprising: (a) a vacuum head having a brush roller chamber throughwhich suction air can flow; (b) a roller brush rotatably mounted in saidbrush roller chamber; and (c) an electric motor for driving said rollerbrush; wherein said vacuum head has a working width measured at outsideedges of said vacuum head transverse to a working direction; whereinsaid brush roller chamber has a bottom with an opening defined byparallel vacuum mouth edges of said brush roller chamber and extendingsubstantially over said working width; and wherein said electric motorhas a maximum power consumption of 80 watts measured at motor idle andsaid working width of said vacuum head exceeds 320 mm.
 2. The electricvacuum brush according to claim 1, wherein said electric motor is apermanent magnet motor.
 3. The electric vacuum brush according to claim1, wherein said vacuum head has a working width of 340 mm to 460 mm. 4.The electric vacuum brush according to claim 1, wherein the electricpower consumption of said electric motor is less than 60 watts at idle.5. A method of designing an electric vacuum brush for a vacuum cleanercomprising the steps of: (a) providing a vacuum head having a brushroller chamber through which suction air can flow, a roller brushrotatably mounted in the brush roller chamber, and an electric motor fordriving the roller brush, said vacuum head having a working widthmeasured at outside edges of said vacuum head transverse to a workingdirection, said brush roller chamber having a bottom with an openingdefined by parallel vacuum mouth edges of said brush roller chamber andextending substantially over said working width; (b) limiting powerconsumption of the electric motor at motor idle to a maximum of 80watts; and (c) fashioning the vacuum head so that the working widthexceeds 320 mm.